In a pan, combine melted butter and flour until a thick paste is formed. Slowly mix in cream from a thick paste to a thin paste and finally a runny sauce. Add salt and black pepper. Bring to a simmer, stirring constantly until thickened and smooth. Add Stilton cheese and stir until melted.

Fry garlic and celery in sunflower oil until softened. Stir into cheese mixture and spoon onto spaghetti. Serve hot with a red and green salad and crusty bread.